Buggy code:
p = Pattern . compile ( "(^|\\})(([^\\{:])+:)+([^\\{]*\\{)" ) ; m = p . matcher ( css ) ; while ( m . find ( ) ) { String s = m . group ( ) ; s = s . replaceAll ( ":" , "___YUICSSMIN_PSEUDOCLASSCOLON___" ) ; s = s . replaceAll ( "\\\\" , "\\\\\\\\" ) . replaceAll ( "\\$" , "\\\\\\$" ) ; m . appendReplacement ( sb , s ) ; } m . appendTail ( sb ) ; css = sb . toString ( ) ; css = css . replaceAll ( "\\s+([!{};:>+\\(\\)\\],])" , "$1" ) ; css = css . replaceAll ( "___YUICSSMIN_PSEUDOCLASSCOLON___" , ":" ) ; css = css . replaceAll ( ":first\\-(line|letter)(\\{|,)" , ":first-$1<seq2seq4repair_space>$2" ) ; css = css . replaceAll ( "\\*//<seq2seq4repair_space>" , "*//" ) ; css = css . replaceAll ( "^(.*)(@charset<seq2seq4repair_space>\"[^\"]*\";)" , "$2$1" ) ; css = css . replaceAll ( "^(\\s*@charset<seq2seq4repair_space>[^;]+;\\s*)+" , "$1" ) ; css = css . replaceAll ( "\\band\\(" , "and<seq2seq4repair_space>(" ) ; css = css . replaceAll ( "([!{}:;>+\\(\\[,])\\s+" , "$1" ) ; css = css . replaceAll ( ";+}" , "}" ) ; css = css . replaceAll ( "([\\s:])(0)(px|em|%|in|cm|mm|pc|pt|ex)" , "$1$2" ) ; css = css . replaceAll ( ":0<seq2seq4repair_space>0<seq2seq4repair_space>0<seq2seq4repair_space>0(;|})" , ":0$1" ) ; css = css . replaceAll ( ":0<seq2seq4repair_space>0<seq2seq4repair_space>0(;|})" , ":0$1" ) ; css = css . replaceAll ( ":0<seq2seq4repair_space>0(;|})" , ":0$1" ) ; sb = new StringBuffer ( ) ; p = Pattern . compile ( "(?i)(background-position|transform-origin|webkit-transform-origin|moz-transform-origin|o-transform-origin|ms-transform-origin):0(;|})" ) ; m = p . matcher ( css ) ; while ( m . find ( ) ) { m . appendReplacement ( sb , ( ( ( m . group ( 1 ) . toLowerCase ( ) ) + ":0<seq2seq4repair_space>0" ) + ( m . group ( 2 ) ) ) ) ; } m . appendTail ( sb ) ; css = sb . toString ( ) ; css = css . replaceAll ( "(:|\\s)0+\\.(\\d+)" , "$1.$2" ) ; p = Pattern . compile ( "rgb\\s*\\(\\s*([0-9,\\s]+)\\s*\\)" ) ; m = p . matcher ( css ) ; sb = new StringBuffer ( ) ; while ( m . find ( ) ) { String [ ] rgbcolors = m . group ( 1 ) . split ( "," ) ; StringBuffer hexcolor = new StringBuffer ( "#" ) ; for ( i = 0 ; i < ( rgbcolors . length ) ; i ++ ) { int val = Integer . parseInt ( rgbcolors [ i ] ) ; if ( val < 16 ) { hexcolor . append ( "0" ) ; } hexcolor . append ( Integer . toHexString ( val ) ) ; } m . appendReplacement ( sb , hexcolor . toString ( ) ) ; } m . appendTail ( sb ) ; css = sb . toString ( ) ; p = Pattern . compile ( ( "(\\=\\s*?[\"\']?)?" + ( "#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])" + "(:?\\}|[^0-9a-fA-F{][^{]*?\\})" ) ) ) ; m = p . matcher ( css ) ; sb = new StringBuffer ( ) ; int index = 0 ; while ( m . find ( index ) ) { sb . append ( css . substring ( index , m . start ( ) ) ) ; boolean isFilter = ( ( m . group ( 1 ) ) != null ) && ( ! ( "" . equals ( m . group ( 1 ) ) ) ) ; if ( isFilter ) { sb . append ( ( ( ( ( ( ( ( ( m . group ( 1 ) ) + "#" ) + ( m . group ( 2 ) ) ) + ( m . group ( 3 ) ) ) + ( m . group ( 4 ) ) ) + ( m . group ( 5 ) ) ) + ( m . group ( 6 ) ) ) + ( m . group ( 7 ) ) ) ) ; } else { if ( ( ( m . group ( 2 ) . equalsIgnoreCase ( m . group ( 3 ) ) ) && ( m . group ( 4 ) . equalsIgnoreCase ( m . group ( 5 ) ) ) ) && ( m . group ( 6 ) . equalsIgnoreCase ( m . group ( 7 ) ) ) ) { sb . append ( ( "#" + ( ( ( ( m . group ( 3 ) ) + ( m . group ( 5 ) ) ) + ( m . group ( 7 ) ) ) . toLowerCase ( ) ) ) ) ; } else { sb . append ( ( "#" + ( ( ( ( ( ( ( m . group ( 2 ) ) + ( m . group ( 3 ) ) ) + ( m . group ( 4 ) ) ) + ( m . group ( 5 ) ) ) + ( m . group ( 6 ) ) ) + ( m . group ( 7 ) ) ) . toLowerCase ( ) ) ) ) ; } } index = m . end ( 7 ) ; } sb . append ( css . substring ( index ) ) ; css = sb . toString ( ) ; sb = new StringBuffer ( ) ; <START_BUG> p = Pattern . compile ( "(?i)(border|border-top|border-right|border-bottom|border-right|outline|background):none(;|})" ) ; <END_BUG>

Fix:
p = Pattern . compile ( "(?i)(border|border-top|border-right|border-bottom|border-left|outline|background):none(;|})" ) ;